The present invention relates to the air channel structure and cold air control of a refrigerator for improving a temperature distribution in a refrigerating chamber.
FIGS. 13 and 15 are sectional views showing a conventional refrigerator as shown in the official gazette of Japanese Patent Laid-Open No. 8-75338. In FIGS. 13 and 15, symbol 1 denotes a refrigerator door, 2 an outer case of the refrigerator made of a steel plate, 3 an inner case formed through vacuum molding of a synthetic resin sheet, 4 a heat insulting material made of polyurethane or the like injected between the outer case 2 and the inner case 3, and 5 a heat insulating partition for separating a refrigerating chamber 6 from a freezing chamber 7.
Symbol 8 denotes a cooling unit, 9 a cooler chamber having the cooling unit 8 inside, 10 a cold air suction channel provided in the heat insulating partition 5, 11 a back cold-air channel for supplying cold air to the refrigerating chamber 6 from the cooler chamber 9, 12 a back damper for controlling the amount of cold air to supply to the back cold-air channel 11, and 13 a back temperature sensor for controlling the operation of the back damper 12 by detecting the air temperature of the back portion in the refrigerator.
Symbol 14 denotes a back blowoff port formed on the back cold-air channel 11 and 15 a refrigerator fan motor set in the cooler chamber 9 for supplying cold air to the back cold-air channel 11.
Symbol 16 denotes a shelf for placing food and the like and back blowoff ports 14 are provided for every compartment partitioned by the shelf 16.
Symbol 17 denotes a shelf supporting rail for mounting the shelf 16, which is integrally formed in the depth direction to the both sides of the inner case 3.
FIG. 14 is a flow chart showing the procedure for controlling the temperature of the refrigerating chamber. When the program starts, a back detected temperature A detected by the back temperature sensor 13 is inputted in step 101 and a back set temperature B of the refrigerating chamber is inputted in step 102 to compare it with the inputted back detected temperature in step 103. When the back detected temperature A is equal to or higher than the back set temperature B, the program goes to step 104 where the back damper 12 is opened to introduce cold air into the refrigerating chamber 6 and returns to step 101. When the back detected temperature A is lower than the back set temperature B, the program goes to step 105 where the back damper 12 is closed to prevent cold air from being introduced into the refrigerating chamber 6 and returns to step 101.
As the size of a refrigerator tends to increase, the importance of food temperature control is stressed. Particularly, when the capacity of the refrigerator is large, the temperature distribution in a storing chamber becomes uneven so that more accurate temperature control is requested. However, because of such constitution of a conventional refrigerator as described above, the food put on the front side of a shelf or in a door pocket provided in the refrigerator is not easily cooled so that a storing condition becomes worse though the food put on the inner part of the shelf is completely cooled. Moreover, there is a problem that the temperature of the food put on the front side of the shelf or in the door pocket rises due to the outside air (warm air) entering the refrigerating chamber whenever the door is opened and closed and therefore, the food is not easily cooled even after the door is closed.